What’s the Moon Made Of? Earth, Most Likely.

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An impact between a Mars-sized protoplanet and early Earth is the most widely-accepted origin of the Moon. Did smaller impacts seed the formation of continents? (NASA/JPL-Caltech)

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Recent research on lunar samples has shown that the Moon may be made of more Earth than green cheese — if by “green cheese” you mean the protoplanet impactor that was instrumental in its creation.

It’s an accepted hypothesis that Earth’s moon was created during an ancient, violet collision between our infant planet and a Mars-sized world called Theia, an event that destroyed Theia and sent part of Earth’s crust and upper mantle into orbit as a brief-lived ring of molten material. This material eventually coalesced to form the Moon, and over the next 4.5 billion years it cooled, became tidally locked with Earth, accumulated countless craters and gradually drifted out to the respectable distance at which we see it today.

Theia’s remains were once assumed to have been a major contributor to the material that eventually formed the Moon.   Lunar samples, however, showed that the ratio of oxygen isotopes on the Moon compared to Earth were too similar to account for such a formation. Now, further research by a team led by scientists from The University of Chicago shows that titanium isotopes — an element much more refractive than oxygen — are surprisingly similar between the Moon and Earth, further indicating a common origin.

“After correcting for secondary effects associated with cosmic-ray exposure at the lunar surface using samarium and gadolinium isotope systematics, we find that the 50Ti/47Ti ratio of the Moon is identical to that of the Earth within about four parts per million, which is only 1/150 of the isotopic range documented in meteorites,” wrote University of Chicago geophysicist Junjun Zhang, lead author of the paper published in the journal Nature Geoscience on March 25.

If the Moon is more Earth than Theia, then what happened to the original impacting body? Perhaps it was made of heavier stuff that sunk deeper into the Moon, or was assimilated into Earth’s mantle, or got lost to space… only more research will tell.

But for now, you can be fairly sure that when you’re looking up at the Moon you’re seeing a piece of Earth, the cratered remnants of a collision that took place billions of years ago.

See the team’s paper here.

Image credit: NASA / JPL-Caltech

Astrophotos: A Colorful Moon

An unusual false color view of our Moon. Credit: César Cantú

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Recognize this? Yes, it is our own Moon, but using Photoshop, the photographer, César Cantú from the Chilidog Observatory in Monterrey, Mexico extracted the Moon’s colors and exaggerated them just a bit. “Although exaggerated, the color components are the real highlights,” César said, “with blue indicating a significant amount of titanium, and the orange areas with little iron or titanium. These colorful images are more easy to perform That thanks to digital cameras that detect colors — where with analog cameras, it is still impossible.”

César took the image on April 6, 2012. See his website for more details.

Want to get your astrophoto featured on Universe Today? Join our Flickr group, post in our Forum or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

“Snowing Microbes” On Saturn’s Moon?

Cassini image of Enceladus from Dec. 2010 (NASA/JPL/SSI)

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Enceladus, Saturn’s 318-mile-wide moon that’s become famous for its ice-spraying southern jets, is on astronomers’ short list of places in our own solar system where extraterrestrial life could be hiding — and NASA’s Cassini spacecraft is in just the right place to try and sniff it out.

On March 27, Cassini came within 46 miles (74 km) of Enceladus’ south pole, the region where the moon’s many active water-ice jets originate from. This was Cassini’s closest pass yet over the southern pole, allowing the spacecraft to use its ion and neutral mass spectrometer — as well as its plasma spectrometer, recently returned to service — to taste the icy spray emanating from deep fissures called “tiger stripes” that scar Enceladus’ surface.

(Fly along with Cassini toward Enceladus’ jets here.)

“More than 90 jets of all sizes near Enceladus’s south pole are spraying water vapor, icy particles, and organic compounds all over the place,” said Carolyn Porco, planetary scientist and Cassini Imaging science team leader. “Cassini has flown several times now through this spray and has tasted it. And we have found that aside from water and organic material, there is salt in the icy particles. The salinity is the same as that of Earth’s oceans.”

In addition to water, salt and organics, there is also a surprising amount of heat — heat generated in part by tidal friction, helping keep Enceladus’ underground water reserves liquid.

“If you add up all the heat, 16 gigawatts of thermal energy are coming out of those cracks,” Porco said.

This creates, in effect, a so-called “Goldilocks zone” of potential habitability orbiting around Saturn… a zone that Cassini has easy access to.

“It’s erupting out into space where we can sample it. It sounds crazy but it could be snowing microbes on the surface of this little world,” Porco said. “In the end, it’s the most promising place I know of for an astrobiology search. We don’t even need to go scratching around on the surface. We can fly through the plume and sample it. Or we can land on the surface, look up and stick our tongues out. And voilà…we have what we came for.”

Cassini's view down into a jetting "tiger stripe" in August 2010

Cassini’s latest results — and images! — from the flyby should be landing on Earth any time now. Stay tuned to Universe Today for more updates on Cassini and Enceladus.

Read more on NASA Science News here.

Image credits: NASA/JPL/SSI.

UPDATE: For images from Cassini’s flyby, showing closeups of Enceladus as well as Dione and Janus, check out the CICLOPS team page here.

1st Student Selected MoonKAM Pictures Look Inspiringly Home to Earth

Student-run MoonKAM Imager Looks Homeward. This image of the far side of the lunar surface, with Earth in the background, was taken by the MoonKAM system board the Ebb spacecraft as part of the first image set taken from lunar orbit from March 15 – 18, 2012. A little more than half-way up and on the left side of the image is the crater De Forest. Due to its proximity to the southern pole, DeForest receives sunlight at an oblique angle when it is on the illuminated half of the Moon. NASA/Caltech-JPL/MIT/SRS

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The first student selected photos of the Moon’s surface snapped by NASA’s new pair of student named Lunar Mapping orbiters – Ebb & Flow – have just been beamed back and show an eerie view looking back to the Home Planet – and all of Humanity – barely rising above the pockmarked terrain of the mysterious far side of our nearest neighbor in space.

Congratulations to Americas’ Youth on an outstanding and inspiring choice !!

The student photo is reminiscent of one of the iconic images of Space Exploration – the first full view of the Earth from the Moon taken by NASA’s Lunar Orbiter 1 back in August 1966 (see below).

The images were taken in the past few days by the MoonKAM camera system aboard NASA’s twin GRAIL spacecraft currently circling overhead in polar lunar orbit, and previously known as GRAIL A and B. The formation-flying probes are soaring over the Moon’s north and south poles.

The nearly identical ships were rechristened as Ebb and Flow after Fourth grade students from the Emily Dickinson Elementary School in Bozeman, Mont., won the honor to rename both spacecraft by submitting the winning entries in a nationwide essay competition sponsored by NASA.

“The Bozeman 4th graders had the opportunity to target the first images soon after our science operations began,” said Maria Zuber, GRAIL principal investigator of the Massachusetts Institute of Technology in Cambridge, Mass., to Universe Today.

“It is impossible to overstate how thrilled and excited we are !”

The initial packet of some 66 student-requested digital images from the Bozeman kids were taken by the Ebb spacecraft from March 15-17 and downlinked to Earth March 20. They sure have lots of exciting classwork ahead analyzing all those lunar features !

“GRAIL’s science mapping phase officially began on March 6 and we are collecting science data,” Zuber stated.

Far Side of Moon Imaged by MoonKAM
This image of the lunar surface was taken by the MoonKAM system onboard NASA’s Ebb spacecraft on March 15, 2012. The 42.3-mile-wide (68-kilometer-wide) crater in the middle of the image (with the smaller crater inside) is Poinsot. Crater Poinsot, named for the French mathematician Louis Poinsot, is located on the northern part of the moon's far side. The target was selected by 4th grade students at Emily Dickinson Elementary School in Montana who had the honor of choosing the first MoonKAM images after winning a nationwide contest. NASA/Caltech-JPL/MIT/SRS

GRAIL’s science goal is to map our Moon’s gravity field to the highest precision ever. This will help deduce the deep interior composition, formation and evolution of the Moon and other rocky bodies such as Earth and also determine the nature of the Moon’s hidden core.

Engaging students and the public in science and space exploration plays a premier role in the GRAIL project. GRAIL is NASA’s first planetary mission to carry instruments – in the form of cameras – fully dedicated to education and public outreach.

Over 2,700 schools in 52 countries have signed up to participate in MoonKAM.

Ebb and Flow - New Names for the GRAIL Twins in Lunar Orbit
4th Grade Students from Bozeman, Montana (inset) won NASA’s contest to rename the GRAIL A and GRAIL B spacecraft and also chose the first lunar targets to be photographed by the onboard MoonKAM camera system. Artist concept of twin GRAIL spacecraft flying in tandem orbits around the Moon to measure its gravity field Credit: NASA/JPL -M ontage: Ken Kremer

5th to 8th grade students can send suggestions for lunar surface targets to the GRAIL MoonKAM Mission Operations Center at UC San Diego, Calif. Students will use the images to study lunar features such as craters, highlands, and maria while also learning about future landing sites.

NASA calls MoonKAM – “The Universe’s First Student-Run Planetary Camera”. MoonKAM means Moon Knowledge Acquired by Middle school students.

The MoonKAM project is managed by Dr Sally Ride, America’s first female astronaut.

“What might seem like just a cool activity for these kids may very well have a profound impact on their futures,” Ride said in a NASA statement. “The students really are excited about MoonKAM, and that translates into an excitement about science and engineering.”

“MoonKAM is based on the premise that if your average picture is worth a thousand words, then a picture from lunar orbit may be worth a classroom full of engineering and science degrees,” says Zuber. “Through MoonKAM, we have an opportunity to reach out to the next generation of scientists and engineers. It is great to see things off to such a positive start.”

MoonKAM image from NASA’s Ebb Lunar Mapping orbiter. This lunar target was selected by the 4th graders at Emily Dickinson Elementary School in Montana who won the contest to rename the GRAIL probes in a nationwide essay contest. NASA/Caltech-JPL/MIT/SRS

Altogether there are eight MoonKAM cameras aboard Ebb and Flow – one 50 mm lens and three 6 mm lenses. Each probe is the size of a washing machine and measures just over 3 feet in diameter and height.

Snapping the first images was delayed a few days by the recent series of powerful solar storms.

“Due to the extraordinary intensity of the storms we took the precaution of turning off the MoonKAMs until the solar flux dissipates a bit,” Zuber told me.

“GRAIL weathered the storm well. The spacecraft and instrument are healthy and we are continuing to collect science data.”

The washing-machine sized probes have been flying in tandem around the Moon since entering lunar orbit in back to back maneuvers over the New Year’s weekend. Engineers spent the past two months navigating the spaceship duo into lower, near-polar and near-circular orbits with an average altitude of 34 miles (55 kilometers) that are optimized for science data collection and simultaneously checking out the spacecraft systems.

Ebb and Flow were launched to the Moon on September 10, 2011 aboard a Delta II rocket from Cape Canaveral, Florida and took a circuitous 3.5 month low energy path to the moon to minimize the overall costs.

The Apollo astronauts reached the Moon in just 3 days. NASA’s next generation Orion space capsule currently under development will send American astronauts back to lunar orbit by 2021 or sooner.

NASA has just granted an extension to the GRAIL mission. Watch for my follow-up report detailing the expanded science goals of GRAIL’s extended lunar journey.

One of the first two remote images of Earth taken from the distance of the Moon on August 23, 1966 by NASA’s Lunar Orbiter 1 spacecraft. Credit: NASA

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March 24 (Sat): Free Lecture by Ken Kremer at the New Jersey Astronomical Association, Voorhees State Park, NJ at 830 PM. Topic: Atlantis, the End of Americas Shuttle Program, Orion, SpaceX, CST-100, Moon and the Future of NASA Human & Robotic Spaceflight

Orion Crew Capsule Targeted for 2014 Leap to High Orbit

The Orion Exploration Flight Test-1 (EFT-1) is scheduled to launch the first unmanned Orion crew cabin into a high altitude Earth orbit in 2014 atop a Delta 4 Heavy rocket from Cape Canaveral, Florida. Artist’s concept. Credit: NASA

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NASA is on course to make the highest leap in human spaceflight in nearly 4 decades when an unmanned Orion crew capsule blasts off from Cape Canaveral, Fla., on a high stakes, high altitude test flight in early 2014.

A new narrated animation (see below) released by NASA depicts the planned 2014 launch of the Orion spacecraft on the Exploration Flight Test-1 (EFT-1) mission to the highest altitude orbit reached by a spaceship intended for humans since the Apollo Moon landing Era.

Orion is NASA’s next generation human rated spacecraft and designed for missions to again take humans to destinations beyond low Earth orbit- to the Moon, Mars, Asteroids and Beyond to deep space.


Orion Video Caption – Orion: Exploration Flight Test-1 Animation (with narration by Jay Estes). This animation depicts the proposed test flight of the Orion spacecraft in 2014. Narration by Jay Estes, Deputy for flight test integration in the Orion program.

Lockheed Martin Space Systems is making steady progress constructing the Orion crew cabin that will launch atop a Delta 4 Heavy booster rocket on a two orbit test flight to an altitude of more than 3,600 miles and test the majority of Orion’s vital vehicle systems.

The capsule will then separate from the upper stage, re-enter Earth’s atmosphere at a speed exceeding 20,000 MPH, deploy a trio of huge parachutes and splashdown in the Pacific Ocean off the west coast of California.

Lockheed Martin is responsible for conducting the critical EFT-1 flight under contract to NASA.

Orion will reach an altitude 15 times higher than the International Space Station (ISS) circling in low orbit some 250 miles above Earth and provide highly valuable in-flight engineering data that will be crucial for continued development of the spaceship.

Orion Exploration Flight Test One Overview. Credit: NASA

“This flight test is a challenge. It will be difficult. We have a lot of confidence in our design, but we are certain that we will find out things we do not know,” said NASA’s Orion Program Manager Mark Geyer.

“Having the opportunity to do that early in our development is invaluable, because it will allow us to make adjustments now and address them much more efficiently than if we find changes are needed later. Our measure of success for this test will be in how we apply all of those lessons as we move forward.”

Lockheed Martin is nearing completion of the initial assembly of the Orion EFT-1 capsule at NASA’s historic Michoud Assembly Facility (MAF) in New Orleans, which for three decades built all of the huge External Fuel Tanks for the NASA’s Space Shuttle program.

In May, the Orion will be shipped to the Kennedy Space Center in Florida for final assembly and eventual integration atop the Delta 4 Heavy rocket booster and launch from Space Launch Complex 37 at nearby Cape Canaveral. The Delta 4 is built by United Launch Alliance.

The first integrated launch of an uncrewed Orion is scheduled for 2017 on the first flight of NASA’s new heavy lift rocket, the SLS or Space Launch System that will replace the now retired Space Shuttle orbiters

Continued progress on Orion, the SLS and all other NASA programs – manned and unmanned – is fully dependent on the funding level of NASA’s budget which has been significantly slashed by political leaders of both parties in Washington, DC in recent years.

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March 24 (Sat): Free Lecture by Ken Kremer at the New Jersey Astronomical Association, Voorhees State Park, NJ at 830 PM. Topic: Atlantis, the End of Americas Shuttle Program, Orion, SpaceX, CST-100 and the Future of NASA Human & Robotic Spaceflight

New Data Find a Silver Lining of Cosmic Radiation

Artist's illustration of the Lunar Reconnaissance Orbiter. CRaTER is the instrument center-mounted at the bottom of LRO. Credit: Chris Meaney/NASA.

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Cosmic radiation, it seems, may be a blessing and a curse. A team of scientists based at the University of New Hampshire have used data from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on NASA’s Lunar Reconnaissance Orbiter (LRO) to measure radiation on the Moon’s surface. They’ve found that while radiation is fatal, it can also cause the chemical changes that form the foundations of biological structures. 

CRaTER was designed to measure and characterize radiation on the Moon. It uses plastic and silicon detectors that mimic human flesh to give scientists an idea of how damaging the environment is to humans; the radiation in this case is from both galactic cosmic rays and solar energetic particles. Both these types of radiation pose a known threat to astronauts and robotic spacecraft alike.

An illustration showing the natural barrier Earth gives us against solar radiation. Credit: NASA.

NASA’s LRO has managed to gather remarkably good data. Its recent measurements were made during a quiet solar period. The lower power, pressure, fluctuations, and magnetic fluctuations of the solar wind means less interruptions. The galactic cosmic rays and solar energy particles have been able to interact more readily with detectors. Since the instruments orbit the Moon, there isn’t even an atmosphere present to shield the blow of these rays and particles.

This is a unique occurrence that has given scientists with sufficient data to validate their models of cosmic radiation. “Now we can… project GCR dose rates from the present period back through time when different interplanetary conditions prevailed,” says Nathan Schwadron, associate professor of physics at the UNH Space Science Center within the Institute for the Study of Earth, Oceans, and Space. These types of projections provide a clearer picture of the effects of cosmic rays on airless bodies throughout the Solar System’s history.

These new, more accurate models can also effectively predict radiation hazards spawned by cosmic rays and solar particles. Schwadron says that these “validated models will be able to answer the question of how hazardous the space environment is and could be during these high-energy radiation events.” Being able to anticipate high radiation events and environments will be necessary for any manned space exploration planned to go beyond low-Earth orbit.

A bootprint on the lunar regolith. Credit: NASA.

But CRaTER’s most recent finding revealed something else interesting: cosmic radiation has another important effect on the bodies it hits. While fatal to humans and damaging to robots, cosmic radiation irradiates water and ice to cause chemical alterations. The process releases oxygen atoms from water ice, which are then free to bind with carbon to form large molecules that are “prebiotic” organic molecules. The radiation process also causes the lunar soil, regolith, to darken over time. This is important in understanding the geologic history of the moon.

The data recorded on radiation environments support the current models of Earth-Moon-Mars interplanetary space. The full paper, titled “Lunar Radiation Environment and Space Weathering from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER),” was written by Schwadron and the director of EOS and lead scientist for the CRaTER instrument Harlan Spence and is published online in the American Geophysical Union’s Journal of Geophysical Research.

Source: University of New Hampshire

Moon Mappers! Contribute to Lunar Science

Want to contribute to lunar science? The MoonMappers citizen science project is now live at CosmoQuest.org, and you can become part of the Lunar Reconnaissance Orbiter’s science team by exploring high-resolution Lunar images and mapping out scientifically interesting features. MoonMappers has been in a testing phase since January, and during the beta period, early participants marked over 150,000 craters and more than 4,000 other interesting features. With your help, scientists will be able to better determine ages of different regions, find historic spikes in the impact rate, determine lunar regolith depth and what may lie under the crust, and make conclusions about the physics of giant explosions on the Moon’s surface.

“Craters can reveal all sorts of different properties about the Moon and planetary surfaces in general,” said project co-science lead Stuart Robbins, from the Southwest Research Institute.
Continue reading “Moon Mappers! Contribute to Lunar Science”

Weekly SkyWatcher’s Forecast – March 19-25, 2012

NGC 2539 - Credit: Palomar Observatory Courtesy of Caltech

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Greetings, fellow SkyWatchers! The week starts off with new Moon and the perfect opportunity to do a Messier Marathon. The planets continue to dazzle as we not only celebrate the Vernal Equinox, but the March Geminid meteor shower as well! If that doesn’t get your pulsar racing – nothing will. It’s time to get out your binoculars and telescopes and meet me in the backyard!

Monday, March 19 – Right now the Moon is between the Earth and the Sun, and you know what that means…New Moon! Tonight we’ll start in northern Puppis and collect three more Herschel studies as we begin at Alpha Monoceros and drop about four fingerwidths southeast to 19 Puppis.

NGC 2539 (Right Ascension: 8 : 10.7 – Declination: -12 : 50) averages around 6th magnitude and is a great catch for binoculars as an elongated hazy patch with 19 Puppis on the south side. Telescopes will begin resolution on its 65 compressed members, as well as split 19 Puppis – a wide triple. Shift about 5 degrees southwest and you find NGC 2479 (Right Ascension: 7 : 55.1 – Declination: -17 : 43) directly between two finderscope stars. At magnitude 9.6 it is telescopic only and will show as a smallish area of faint stars at low power. Head another degree or so southeast and you’ll encounter NGC 2509 (Right Ascension: 8 : 00.7 – Declination: -19 : 04) – a fairly large collection of around 40 stars that can be spotted in binoculars and small telescopes.

Tuesday, March 20 – Today is Vernal Equinox, one of the two times of the year that day and night become equal in length. From this point forward, the days will become longer – and our astronomy nights shorter! To the ancients, this was a time a renewal and planting – led by the goddess Eostre. As legend has it, she saved a bird whose wings were frozen from the winter’s cold, turning it into a hare which could also lay eggs. What a way to usher in the northern spring!

With the Moon still out of the picture, let’s finish our study of the Herschel objects in Puppis. Only three remain, and we’ll begin by dropping south-southeast of Rho and center the finder on a small collection of stars to locate NGC 2489 (Right Ascension: 7 : 56.2 – Declination: -30 : 04). At magnitude 7, this bright collection is worthy of binoculars, but only the small patch of stars in the center is the cluster. Under aperture and magnification you’ll find it to be a loose collection of around two dozen stars formed in interesting chains.

The next are a north-south oriented pair around 4 degrees due east of NGC 2489. You’ll find the northernmost – NGC 2571 (Right Ascension: 8 : 18.9 – Declination: -29 : 44) – at the northeast corner of a small finderscope or binocular triangle of faint stars. At magnitude 7, it will show as a fairly bright hazy spot with a few stars beginning to resolve with around 30 mixed magnitude members revealed to aperture. Less than a degree south is NGC 2567 (Right Ascension: 8 : 18.6 – Declination: -30 : 38). At around a half magnitude less in brightness, this rich open cluster has around 50 members to offer the larger telescope, which are arranged in loops and chains.

Congratulations on completing these challenging objects!

Are you up for another challenge? Then test your ability to judge magnitude as Mars has now dimmed to approximately -1.0. Does it look slightly different in size and brightness than it did a week or so ago? Keep watching!

Wednesday, March 21 – Take your telescopes or binoculars out tonight to look just north of Xi Puppis for a celebration of starlight known as M93 (Right Ascension: 7 : 44.6 – Declination: -23 : 52). Discovered in March of 1781 by Charles Messier, this bright open cluster is a rich concentration of various magnitudes that will simply explode in sprays of stellar fireworks in the eyepiece of a large telescope. Spanning 18 light-years of space and residing more than 3400 light-years away, it contains not only blue giants, but lovely golds as well. Jewels in the night…

Thursday, March 22 – Today in 1799 Friedrich Argelander was born. He was a compiler of star catalogues, studied variable stars and created the first international astronomical organization.

Tonight let’s celebrate no Moon and have a look at an object from an alternative catalog that was written by Lacaille, and which is about two fingerwidths south of Eta Canis Majoris.

Also known as Collinder 140, Lacaille’s 1751 catalog II.2 “nebulous star cluster” is a real beauty for binoculars and very low power in telescopes. More than 50% larger than the Full Moon, it contains around 30 stars and may be as far as 1000 light-years away. When re-cataloged by Collinder in 1931, its age was determined to be around 22 million years. While Lacaille noted it as nebulous, he was using a 15mm aperture reflector, and it is doubtful that he was able to fully resolve this splendid object. For telescope users, be sure to look for easy double Dunlop 47 in the same field.

Now, kick back and enjoy a spring evening with two meteor showers. In the northern hemisphere, look for the Camelopardalids. They have no definite peak, and a screaming fall rate of only one per hour. While that’s not much, at least they are the slowest meteors – entering our atmosphere at speeds of only 7 kilometers per second!

Far more interesting to both hemispheres will be the March Geminids which peak tonight. They were first discovered and recorded in 1973 and then confirmed in 1975. With a much faster fall rate of about 40 per hour, these slower than normal meteors will be fun to watch! When you see a bright streak, trace it back to its point of origin. Did you see a Camelopardalid, or a March Geminid?

Friday, March 23 – Today in 1840, the first photograph of the Moon was taken. The daguerreotype was exposed by American astronomer and medical doctor J. W. Draper. Draper’s fascination with chemical responses to light also led him to another first – a photo of the Orion Nebula.

Our target for tonight is an object that’s better suited for southern declinations – NGC 2451 (Right Ascension: 7 : 45.4 – Declination: -37 : 58). As both a Caldwell object (Collinder 161) and a southern skies binocular challenge, this colorful 2.8 magnitude cluster was probably discovered by Hodierna. Consisting of about 40 stars, its age is believed to be around 36 million years. It is very close to us at a distance of only 850 light-years. Take the time to closely study this object – for it is believed that due to the thinness of the galactic disk in this region, we are seeing two clusters superimposed on each other.

With the Moon out of the picture early, why not get caught up in a galaxy cluster study – Abell 426. Located just 2 degrees east of Algol in Perseus, this group of 233 galaxies spread over a region of several degrees of sky is easy enough to find – but difficult to observe. Spotting Abell galaxies in Perseus can be tough in smaller instruments, but those with large aperture scopes will find it worthy of time and attention.

At magnitude 11.6, NGC 1275 (Right Ascension: 3 : 19.8 – Declination: +41 : 31) is the brightest of the group and lies physically near the core of the cluster. Glimpsed in scopes as small as 150 mm aperture, NGC 1275 is a strong radio source and an active site of rapid star formation. Images of the galaxy show a strange blend of a perfect spiral being shattered by mottled turbulence. For this reason NGC 1275 is thought to be two galaxies in collision. Depending on seeing conditions and aperture, galaxy cluster Abell 426 may reveal anywhere from 10 to 24 small galaxies as faint as magnitude 15. The core of the cluster is more than 200 million light-years away, so it’s an achievement to spot even a few!

Saturday, March 24 – Today is the birthday of Walter Baade. Born in 1893, Baade was the first to resolve the Andromeda galaxy’s individual stars using the Hooker telescope during World War II blackout times, and he also developed the concept of stellar populations. He was the first to realize that there were two types of Cepheid variables, thereby refining the cosmic distance scale. He is also well known for discovering an area towards our galactic center which is relatively free of dust, now known as “Baade’s Window.”

Just after sunset, you really need to take a look out your western window for a really beautiful bit of scenery. As the sky darkens, look for the very tender crescent Moon lit with “Earthshine”. Above it you will see bright Jupiter. Above that you will see blazing Venus. And, if that’s not enough, just a little higher will bring you to the Pleiades! What a great way to start a weekend evening!

With the Moon so near the horizon, we have only a short time to view its features. Tonight let’s start with a central feature – Langrenus – and continue further south for crater Vendelinus. Spanning 92 by 100 miles and dropping 14,700 feet below the lunar surface, Vendelinus displays a partially dark floor with a west wall crest catching the brilliant light of an early sunrise. Notice also that its northeast wall is broken by a younger crater – Lame. Head’s up! It’s an Astronomical League challenge.

Once the Moon has set, revisit M46 in Puppis – along with its mysterious planetary nebula NGC 2438. Follow up with a visit to neighboring open cluster M47 – two degrees west-northwest. M47 may actually seem quite familiar to you already. Did you possibly encounter it when originally looking for M46? If so, then it’s also possible that you met up with 6.7 magnitude open cluster NGC 2423 (Right Ascension: 7 : 37.1 – Declination: -13 : 52), about a degree northeast of M47 and even dimmer 7.9 magnitude NGC 2414 (Right Ascension: 7 : 33.3 – Declination: -15 : 27 ) as well. That’s four open clusters and a planetary nebula all within four square arc-minutes of sky. That makes this a cluster of clusters!

Let’s return to study M47. Observers with binoculars or using a finderscope will notice how much brighter, and fewer, the stars of M47 are when compared to M46. This 12 light-year diameter compact cluster is only 1600 light-years away. Even as close as it is, not more than 50 member stars have been identified. M47 has about one tenth the stellar population of larger, denser, and three times more distant, M46.

Of historical interest, M47 was “discovered” three times: first by Giovanni Batista Hodierna in the mid-17th century, then by Charles Messier some 17 years later, and finally by William Herschel 14 years after that. How is it possible that such a bright and well-placed cluster needed “re-discovery?” Hodierna’s book of observations didn’t surface until 1984, and Messier gave the cluster’s declination the wrong sign, making its identification an enigma to later observers – because no such cluster could be found where Messier said it was!

Sunday, March 25 – Today in 1655, Titan – Saturn’s largest satellite – was discovered by Christian Huygens. He also discovered Saturn’s ring system during this same year. 350 years later, the probe named for Huygens stunned the world as it reached Titan and sent back information on this distant world. How about if we visit Saturn? You’ll find the creamy yellow planet located about a fistwidth northwest of bright, white Spica! Even a small telescope will reveal Titan, but remember… it orbits well outside the ring plane, so don’t mistake it for a background star! While you’re there, look closely around the ring edges for the smaller moons. A 4.5” telescope can easily show you three of them. How about the shadow the rings on the planet’s surface? Or how about the shadow of the planet on the rings? Is the Cassini division visible? If you have a larger telescope, look for other ring divisions as well. All are part and parcel of viewing incredible Saturn!

If you missed yesterday evening’s scenic line-up, don’t despair. Just after the Sun sets tonight – and above the western horizon – you’ll find the young Moon very closely paired with Jupiter. Keep traveling eastward (up) and you’ll encounter Venus. Continue east and the next stop is M45. Watch in the days ahead as the Moon sweeps by, continuing to provide us with a show! Need more? Then check out Leo and Mars! You’ll find a great triangulation of Regulus to the west, Mars to the east and Algieba to the north. If you didn’t know better, you’d almost swear the Lion swallowed the red planet.

Tonight let’s return to our previous studies of the Moon and revisit a challenging crater. Further south than Vendelinus, look for another large, mountain-walled plain named Furnerius, located not too far from the terminator. Although it has no central peak, its walls have been broken numerous times by many smaller impacts. Look at a rather large one just north of central on the crater floor. If skies are stable, power up and search for a rima extending from the northern edge. Keep in mind as you observe that our own Earth has been pummeled just as badly as its satellite.

On this day in 1951, 21 cm wavelength radiation from atomic hydrogen in the Milky Way was first detected. 1420 MHz H I studies continue to form the basis of a major part of modern radio astronomy. If you would like to have a look at a source of radio waves known as a pulsar, then aim your binoculars slightly more than a fistwidth east of bright Procyon. The first two bright stars you encounter will belong to the constellation of Hydrus and you will find pulsar CP0 834 just above the northernmost – Delta.

Unitl next week? May all your journeys be at light speed!

Solving the Puzzle of Apollo 12’s Mysterious Magnetic Moon Rocks

The moon's largest grouping of magnetic anomalies, on the left, is near the northern rim of the South Pole-Aitken basin, which scientists believe was created by the impact of a massive asteroid about 4.5 billion years ago. Image Credit: NASA/LRO/Science/AAAS

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Ever since their discovery by the Apollo 12 crew, scientists have been puzzled by strongly magnetized rocks found on the Moon. Most Moon rocks that were brought back by the Apollo missions have very little iron, and therefore lack the ability to be strongly magnetized. At first, the magnetic oddities didn’t appear to be related to any lunar geology such as craters or lava flows. Over time, additional lunar missions have provided more data showing that only some portions of the Moon’s crust have magnetic fields. A team of scientists now theorize that the magnetized “patches” on the lunar surface may be the remains of an asteroid that crashed into the Moon shortly after its formation nearly 4.5 billion years ago. The impact crater, known as the South Pole-Aitken basin is one of the largest known in our Solar System.

Mark Wieczorek (Paris Institute for Global Physics), describes the South Pole-Aitken basin as, “this huge, whopping crater that’s roughly half the size of the U.S,” and says it may hold the answers to the mystery of the Apollo 12 rocks.

The Apollo 12 landing site as seen by LRO. Credit: NASA/GSFC/Arizona State University

Studies of the basin show that it is elliptical which suggests the impact was by a large object that hit at an oblique angle. Wieczorek speculates that the impactor was 10% to 30% iron by weight and about 100 times more magnetic than the lunar regolith. Interestingly enough, the theorized impact angle would have flung debris from the object in a pattern very similar to the observed magnetic anomalies. The material could have been magnetized as it cooled by a magnetic field that may have existed early in our Moon’s history.

Wieczorek and his team set out to test their theories with computer simulations of different types of impacts. The research led to a scenario where an object struck the Moon at about a 45 degree angle with a velocity of 15 kilometers per second. The team’s best impact model was described as normal by Wieczorek who stated, “We don’t require improbable conditions.”

Now the team needs to address one other question: How and when did a magnetic field develop on the Moon?

Wieczorek offers a simple solution: Go back to the moon and collect samples.

Source: NASA Lunar Science Institute

Go On a Grand Tour of the Moon

Take a "peak" into Tycho Crater!


To honor the Lunar Reconnaissance Orbiter’s amazing 1,000 days in science-filled orbit, the LRO team at Goddard Space Flight Center has created a wonderful video tour of the lunar surface like you’ve never seen it before!

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“Tour of the Moon” takes viewers to several breathtaking locations on the Moon, including Orientale Basin, Shackleton crater, Tycho crater, Aristarchus Plateau, Mare Serenitatis, Compton-Belkovich volcano, Tsiolkovsky crater and more. The fully narrated video is above, and clips from each of the stops on the tour are available in many other formats here.

In addition, another video highlighting the dramatic evolution of the Moon was released today… you can view the full narrated version in 2D and stereoscopic 3D here.

iPad owners can also download the NASA Viz app to see this and other NASA stories, updated twice a week.

Credit: NASA Goddard Space Flight Center